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arma3:terrain:satellite-image-resolution-size-explained

Satellite Image Resolution Size Explained

2020-05-16 Update

Why is my terrain's satellite texture very low quality!? frequently asked question - answered!

Anybody who has computer hardware to run ArmA 2 / ArmA 3 can edit about 20480 x 20480 resolution satellite images in photoshop or gimp. This resolution is enough to do decent enough 40km x 40km terrains, but you are recommended to use higher resolution (read below).

Satellite texture/mask resolution is not an really issue, unless you are creating a huge terrain, perhaps above 50km, then you need to split satellite into 2 x 2, 4 x 4 etc tiles (read below).

This page is about satellite texture/mask image resolutions, if you are looking for terrain sizes then please refer to Terrain Grid and Cell Sizes.

Recommended 1 meter / 1 pixel

Recommended sizes (1m / pixel):

Kilometers Satellite Resolution
2.5 2560
5 5120
7 7168
10 10240
15 15360
20 20480
40 40960
81 81920

Once you go well over 20480 resolution image size you need to split it up to smaller tiles and import satellite texture / mask as tiles.

Meter / Pixel Ratio

If you place one satellite texture / mask resolution pixel into one meter of terrain, that is very good quality and recommended.

When you start to increase that ratio, you stretch that texture over to wider area, 2, 5, 10 or whatever the ratio would be and then you get lower and lower quality the further you stretch pixel above terrain meters.

There is really no reason to use low quality meters per pixel scale, use one that is a good high quality scale.

Meter / Pixel Quality
0.5 Crazy good, rarely used
1 Good, recommended
2 Good
3-5 Okay
5-10 Low
10+ Very low, don't use

It is up to you to decide what ratio to use, what quality do you want.

Now some might already run away scared when we talk about 40960 resolution images and many think even 20km is too large terrain. But that has nothing to do with the fact that the larger your terrain, the closer you are to photoshop / gimp editing limits like the mentioned 40960 resolution for single images with limited RAM.

Pixel and Resolution

Satellite meters / pixel vs satellite texture resolution

Following table gives you some idea how the satellite texture resolution increases as you increase meters / pixel ratio.

Terrain Size Kilometers Meter / Pixel Satellite Texture Resolution
1 1 1024
2 1 2048
3 1 3072
4 1 4096
5 1 5120
10 1 10240
15 1 15360
20 1 20480
30 1 30720
40 1 40960
50 1 51200
60 1 61440
1 2 512
2 2 1024
3 2 1536
4 2 2048
5 2 2560
10 2 5120
15 2 7680
20 2 10240
30 2 15360
40 2 20480
50 2 25600
60 2 30720

Huge Satellite Texture Sizes

Miro (the bis dev who made Take On Helicopters South Asia terrain) said that TOH South Asia satellite was 61,000 x 61,000 resolution and it worked fine.

In 2018 the arma(1) terrain / object making legend Opteryx, have 64gb ram in his monster computer and he used photoshop to edit 102,400 x 102,400 resolution image. He attempted to edit 150,000 resolution image as well but without extensive SSD hardware support it was borderline unusable.

In 2010s when we (PMC + some guys in arma2 community) did experiment with 40960 satellite texture resolutions, it was borderline doable with photoshop (we didn't use gimp back then), but even then saving took several minutes while photoshop swapped to the disk like a crazy. This was with 16gb ram on win 7 64bit.

Now with terrain builder we can import satellite texture / mask as tiles which eases the load while compiling our WRP (back in arma2 visitor3 we had no such option).

PMC terrains use 1 or 2 meter per pixel scale pretty much on all terrains (if some leftovers are using larger those will be upgraded in the future). Our older 143km terrains use 2m/px but the newer terrains use strictly 1m/px for example PMC Suwalki Gap is 81km with 81,920 x 81,920 resolution satellite and the mega monster PMC Iran Jahrom is 163,840 x 163,840 res and the craziest terrain of all PMC Mongolia uses 204,800 x 204,800 resolution satellite (yes, it was not a typo, it really is 204k res).

PMC terrains in general for 40km size use 2 x 2 tiles, above that its 4 x 4 tiles and some of these special mega monster experiments use 8 x 8 and even 16 x 16 tiles (I believe PMC Mongolia uses 16×16 tiles).

Terrain Builder's ability to load satellite as tiles is awesome, please use it to your advantage on larger terrains. No longer you are limited to what photoshop and gimp can load, just edit the satellite in smaller tiles.

So the bottom line is, your computers RAM dictates what size of single image satellite texture / mask you can do, this limit is removed if you split satellite into smaller image tiles. Use only 1 meter per pixel scale and you're fine.

arma3/terrain/satellite-image-resolution-size-explained.txt · Last modified: 2020-05-16 11:36 by snakeman